Automotive coolant control valve

ABSTRACT

A coolant flow valve for controlling the distribution and flow of coolant to replace the radiator thermostat and heater valve currently used in automotive applications. The valve includes a valve rotor rotationally received in a valve housing wherein the rotational orientation thereof determines which combination of flow paths through four different outlet ports is selected.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation application of U.S. patentapplication Ser. No. 09/997,118 filed Nov. 28, 2001, now U.S. Pat. No.6,681,805 currently pending.

BACKGROUND OF INVENTION

The present invention generally relates to a valve for controlling theflow of fluid and more particularly pertains to a valve forsimultaneously controlling the distribution and flow of an automobile'scoolant through multiple flow paths.

Water-cooled internal combustion engines that are used in automobilesrely on a fluid to carry excess heat from the engine to an external heatexchanger commonly referred to as the radiator. Such coolant iscontinuously recirculated through the engine until its temperatureexceeds a preselected level at which point a portion of the flow isrouted through the heat exchanger. The flow to the radiator iscontinuously adjusted in order to maintain the temperature of thecoolant within a desired range. The heat carried by the fluid is alsoused to heat the interior of the automobile whereby a portion of thecirculating coolant is routed through a second heat exchanger positionedso as to heat air that is directed into or recirculated within thepassenger compartment.

The distribution of the flow of coolant that is generated by anengine-driven water pump is typically controlled by two separatecomponents, namely a radiator thermostat and a heater valve. Heretoforeused thermostats typically rely on a mechanism that causes the forcegenerated by the expansion of mass of wax-like material to overcome thebias of a spring to open a valve wherein the wax-like material expandsas a function of temperature. The entire device is immersed in the flowof coolant and is positioned and configured so as to block off the flowof coolant to the radiator when the valve is closed. While the valve isin its closed position, the coolant continues to circulate but is forcedto bypass the radiator and is redirected back into the engine's waterpassages. A number of disadvantages are associated with this type ofconfiguration including, but not limited to, the fact that the bypassflow path remains open at all times and that a portion of the flow ofcoolant therefore always bypasses the radiator even if maximum coolingis called for. Additionally, the positioning of the thermostat directlyin the flow path of the coolant poses an impediment to the flow ofcoolant and thereby compromises the efficiency of the cooling systemwhile the failure of the opening mechanism typically results in thethermostat remaining in its closed configuration which can quickly leadto engine damage. Another disadvantage inherent in heretofore usedthermostat configurations is the fact that the device can necessarilyonly respond to the temperature of the coolant rather than directly tothe temperature of the engine, let alone the anticipated cooling needsof the engine. The engine temperature may therefore not necessarily beoptimized for a variety of conditions, which may result in decreasedfuel efficiency and increased exhaust emissions.

Heater valves are typically positioned so as to direct a portion of theflow of coolant to a heater core positioned within the HVAC system ofthe automobile. Early heating systems included a valve that was simplyactuated by a cable extending from a lever positioned in the interior ofthe automobile. Many modern systems employ computer controlled servooperated valves, wherein the valve position is either modulated so as tocontrol the temperature of the heater or subject to either a fully openor fully closed position wherein air heated by the heater issubsequently mixed with cooled air to regulate the temperature withinthe passenger compartment.

A difficulty associated with this heretofore approach toward controllingthe flow and distribution of coolant is inherent in the fact that, ineffect, two independently operating systems are affecting thetemperature of a common coolant. A change in the demand for heat withinthe passenger cabin will effect the temperature of the coolant as willthe position of the thermostat. A change in one will necessarily inducea change in the other and without a common control system, thetemperature may tend to fluctuate and dither. Variations in engine load,especially in for example in stop-and-go traffic will introduce evenmore fluctuation as the heat fed into the system will additionally besubject to variation. Increasingly strict emission regulations anddemands for higher fuel efficiencies require the engine to operate innarrower temperature ranges which requires a more precise control ofcoolant temperature. An improved cooling system is needed with whichcoolant temperature and hence engine and heater temperature can be moreprecisely controlled.

SUMMARY OF INVENTION

The valve of the present invention overcomes the shortcomings ofpreviously known coolant flow and distribution control systems. A singlevalve replaces the presently used separate thermostat and heater valvedevices and provides for the comprehensive control of the routing andflow of circulating coolant. The valve controls the flow of coolant tothe radiator, the amount of flow that bypasses the radiator to bereintroduced into the engine's cooling passages, the flow of coolant tothe heater and additionally provides for the degassing of the coolantflowing through the valve. All such functions are achieved by a singlevalve as described herein.

The valve of the present invention includes a valve rotor that isrotationally received within a valve housing. The housing includes aninlet port and a number of outlet ports formed therein while the valverotor has a number of conduits extending therethrough that serve to setthe inlet port into fluid communication with a selected combination ofoutlet ports as a function of the rotational orientation of the valverotor within the valve housing.

More particularly, the valve of the present invention is configured suchthat the ports that are formed in the cylindrical valve housing arearranged along at least two planes that are spaced along the axis of thehousing. A first plane may include the inlet port and an outlet port forflow to the radiator. Ports arranged along a second plane may include aheater outlet port and a bypass port. A port for carrying gas bubblesmay be formed in an end of the cylindrical housing. The conduits formedin the valve rotor are arranged such that selected conduits becomealigned with selected ports as a function of the rotational orientationof the valve rotor within the valve housing. An internal conduit extendsalong the axis of the valve rotor so as to interconnect conduits thatarranged along the two planes.

The precise rotational orientation of the valve rotor within the valvehousing required to achieve a certain distribution and flow of coolantmay be achieved by the operation of a stepper motor. Inputs receivedfrom one or more temperature sensors and from an operator with regard toa selected heater temperature may be interpreted by a microprocessor togenerate a signal necessary to drive the motor to a desired position. Amechanical spring may additionally be employed to force the valve rotorto assume a rotational orientation for providing maximum flow to theradiator and heater in the event a failure of the electronics takesplace to serve as a fail safe mode.

These and other features and advantages of the present invention willbecome apparent from the following detailed description of a preferredembodiment which, taken in conjunction with the accompanying drawings,illustrates by way of example the principles of the invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a valve assembly that includes apreferred embodiment of the valve of the present invention;

FIG. 2 is a perspective view of the valve;

FIG. 3 is a perspective view of the valve rotor;

FIG. 4 is a cross-sectional view of the valve rotor taken along lines4—4 of FIG. 3;

FIG. 5 is a cross-sectional view of the valve rotor taken along lines5—5 of FIG. 3;

FIG. 6 is a bottom plan view of the valve rotor shown in FIG. 3;

FIG. 7 is an enlarged cross-sectional view taken along lines 7—7 of FIG.2;

FIG. 8 is a cross-sectional view of the valve rotor within the valvehousing taken along the same plane as illustrated in FIG. 4 and rotatedto its maximum counter-clockwise rotational orientation;

FIG. 9 is a cross-sectional view of the valve rotor within the valvehousing taken along the same plane as is illustrated in FIG. 5 and inthe same rotational orientation of the valve rotor vis-a-vis the valvehousing as is shown in FIG. 8;

FIG. 10 is a cross-sectional view of the valve rotor within the valvehousing taken along the same plane as illustrated in FIG. 4 and in itsmaximum clockwise rotational orientation;

FIG. 11 is a cross-sectional view of the valve rotor within the valvehousing taken along the same plane as is illustrated in FIG. 5 and inthe same rotational orientation of the valve rotor vis-a-vis the valvehousing as is shown in FIG. 10; and

FIG. 12 is a graphic representation of the various flow paths as afunction of rotational orientation.

DETAILED DESCRIPTION

The valve of the present invention replaces a conventional radiatorthermostat and heater valve that are typically employed in modernautomobiles. The valve controls the flow and distribution of coolant tothe radiator, radiator bypass and heater and may optionally control thedegassing of the coolant.

FIG. 1 is a perspective view of a valve assembly 12 that includes thevalve 14 of the present invention. The valve controls the flow ofcoolant therethrough, wherein coolant entering through inlet port 16 isdistributed via a preselectable combination of outlet ports 18, 20, 22,24. Setting the inlet port into fluid communication with a desiredcombination of outlets ports is achieved via the operation of anassociated drive mechanism 26 which may take the form of a stepper motorand reduction gear combination.

FIG. 2 is a perspective view of the valve 14 sans drive mechanism. Thevalve includes a valve rotor 28 that is rotationally received within avalve housing 30. The valve housing has a plurality of ports formedtherein, including an inlet port 16, a radiator port 18, a bypass port20, a heater port 22 and a degassing port 24. Each of the ports extendthrough the wall of the housing to define a conduit to its interior. Theaxis 32 of the inlet port and the axis 34 of the radiator port arealigned with one another and lie on a first plane that is perpendicularto the central axis 36 of the cylindrical valve. The axis 38 of thebypass port and the axis 40 of the heater port lie on a second planethat is perpendicular to the central axis wherein such second plane isaxially displaced relative to the first plane. The axis 42 of thedegassing port extends from the base of the valve housing, is generallyparallel to the central valve axis 36 and radially offset therefrom. Inthe embodiment illustrated, each of the ports has a length of barbedtubing 43, 44, 45 of appropriate length and diameter extending therefromconfigured for receiving a coolant carrying hose or line that may befitted and clamped thereto. The rotational orientation of the valverotor within the valve housing determines which outlet ports are setinto fluid communication with the inlet port. A shaft 46 extends fromone end of the valve rotor along its axis 36 to facilitate its rotationby the drive mechanism. A return spring 47 disposed about the shaftserves to bias the valve rotor into a preselected rotational orientationrelative to the valve housing.

FIG. 3 is a perspective view of the valve rotor 28 of the valve 14 ofthe present invention. The valve rotor has a number of internal fluidpassages formed therein that are interconnected to one another withinthe interior of the valve rotor and to various openings 48, 50, 52formed on the surface of the valve rotor. The openings arecircumferentially as well as axially spaced relative to one another inprecisely defined locations so as to become aligned with selected portsformed in the valve housing 30 at preselected rotational orientations ofthe valve rotor relative to the valve housing.

FIG. 4 is a cross-sectional view of valve rotor 28 taken along lines 4—4of FIG. 3. Clearly visible is a T-shaped fluid passage 54 formed thereinthat extends through the interior of the valve rotor and to its surfacevia openings 48, 50 and 56. A central fluid passage 58 extends downalong the central axis of the valve rotor. The rotational orientation ofthe valve rotor within the valve housing 30 will determine which of theopenings 48, 50 and 56 is to be set into fluid communication withradiator port 18 and what percentage of the cross-sectional area of suchopening is to be aligned therewith.

FIG. 5 is a cross-sectional view of the valve rotor 28 taken along lines5—5 of FIG. 3. The pie-shaped fluid passage 60 serves to set the centralfluid passage into fluid communication with the elongated opening 52formed on the surface of the rotor as well as with the small axiallyextending fluid passages 62, 64. The rotational orientation of the valverotor within the valve housing 30 will determine whether the bypass port20 or the heater port 22 or both ports are to be aligned with all or aportion of opening 52.

FIG. 6 is a bottom plan view of the valve rotor 28 showing the twogrooves 66, 68 formed in the base of the component. The grooves are influid communication with fluid passages 62, 64, which extend into fluidpassage 60. The rotational orientation of the valve rotor within thevalve housing 30 will determine whether one of the grooves is set intofluid communication with the degassing port 24 formed in the base of thevalve housing.

Seals are fitted about each of the outlet ports so as to limit the flowof fluid therethrough to only fluid that issues from an opening formedin the valve rotor 28 that is wholly or partially aligned therewith.FIG. 7 is an enlarged cross-sectional view taken along line 7—7 of FIG.2 illustrating the seal configuration employed for heater port 22 whichis identical to that which is employed for the radiator port 18 as wellas the bypass port 20. Each of such ports includes a section of tubing44 (or 43, 45) that extends outwardly and is configured for receivingand retaining a hose or other conduit clamped thereto. Each such sectionof tubing includes a neck portion 72 of reduced diameter disposed nearits proximal end that terminates so as to be approximately aligned withthe inner diameter of the valve housing 30. A flexible seal 70 includesa collar 74 is tightly fitted about the neck portion as well as a flange76 that engages the surface of the valve rotor 28. The seal isconfigured such that the coolant which is present in the space 78between the valve rotor and the valve housing serves to backload theseal so as to urge the flange against the valve rotor and thereby forman effective seal. A simple O-ring (not shown) serves to form a sealabout the proximal end of the degassing port 24. A simple gasket (notshown) serves to form a seal between the upper flange 80 of the valvehousing and a cooperating surface that may extend from the enclosure forthe drive mechanism. An additional O-ring (not shown) is fitted aboutshaft 46 to form a seal with a cooperating surface of the enclosure forthe drive mechanism to complete the seal of the valve housing.

In use, the valve of the present invention is plumbed such that theinlet port 16 receives the output from the water pump that is used tocirculate an engine's coolant. The pump may comprise an engine driven orelectrically driven device. The radiator port 18, bypass port 20 andheater port 22 are each plumbed to the respective components while thedegassing port 24 is plumbed so as to most advantageously remove bubblesfrom the circulating coolant as is appropriate for a particular coolingsystem such as by connection to an overflow tank. Conventional hoses andhose clamps may be used to make the various connections. Any of a widevariety of control configurations may be employed to rotate the valverotor 28 within the valve housing 30 in order to achieve a desiredeffect. A microprocessor receiving inputs from various sensors,including for example temperature sensors, as well as input from anoperator, including for example a desired cabin temperature setting,determines which rotational orientation of the valve rotor within thevalve housing would provide the appropriate amount of coolant flowthrough the various flow paths. The drive mechanism can then be providedwith the appropriate signal in order to rotate the valve rotor into theproper orientation.

FIGS. 8 and 9 are cross-sectional views of a preferred embodiment of thevalve of the present invention wherein the valve housing 28 is rotatedto its extreme counter-clockwise position within the valve housing 30.FIG. 8 is a cross-sectional view along the plane that includes the axis32 of the inlet port 16 and the axis 34 of the radiator port 18. FIG. 9is a cross-sectional view along the plane that includes the axis 38 ofthe bypass port 20 and the axis 40 of the heater port 22. Fluid enteringinlet port 16 is free to enter the valve rotor 28 through any of theunobstructed openings. While the most direct path is via opening 48, thegap 78 between the valve rotor and the valve housing also provides fluidpaths to openings 50, 52 and 56. In this particular rotationalorientation only a small percentage of one of the outlet ports, namelyradiator port 18 is aligned with openings (50, 56) formed in the valverotor. Radiator port seal 82 prevents unobstructed flow along gap 78into the radiator port while bypass port seal 84 and heater port seal 86precludes any flow into the respective ports.

FIGS. 10 and 11 are cross-sectional views of a preferred embodiment ofthe valve of the present invention wherein the valve housing 28 isrotated to its extreme clockwise position within the valve housing 30which represents a rotation of approximately 225 degrees from therotational orientation shown in FIGS. 8 and 9. FIG. 10 is across-sectional view along the plane that includes the axis 32 of theinlet port 16 and the axis 34 of the radiator port 18. FIG. 11 is across-sectional view along the plane that includes the axis 38 of thebypass port 20 and the axis 40 of the heater port 22. Fluid enteringinlet port 16 is free to enter the valve rotor 28 through any of theunobstructed openings. While the most direct flow path is via opening56, the gap 78 between the valve rotor and the valve housing alsoprovides flow paths to openings 50 and 52. In this particular rotationalorientation an unobstructed flow path is provided to both the radiatorvia opening 48 and radiator port 18 and to the heater via central fluidpassage 58, opening 52 and heater port 22. Flow to the bypass port 20 iscompletely blocked off and sealed by bypass port seal 84. As such, thisrotational orientation provides for maximum engine cooling and is usedas a default or failsafe mode. In the event of a controller or otherelectrical malfunction, mechanical spring 47 serves to rotate the valverotor into this orientation.

FIG. 12 is graphic representation of the various flow paths that areestablished as a function of the rotational orientation of the valverotor 28 within the valve housing 30. The horizontal axis represents therotational orientation of the valve rotor in degrees while the verticalaxis represents the approximate open area that is available for the fourdifferent outlets. The radiator outlet is denoted by diamonds, theheater by the squares, the bypass by the triangles and the degas by the“X's.” The cross-sectional illustrations of FIGS. 8 and 9 arerepresented by the 0 degree position while the cross-sectionalillustrations of FIGS. 10 and 11 are represented by the 225 degreeposition.

The valve configuration of the present invention allows a variety ofdifferent flow path combinations to be selected, including:

a. Bypass only with Degas closed;

b. Heater only with Degas closed;

c. Heater and Bypass open with Degas open;

d. Bypass open with Radiator blended and Degas open;

e. Heater open with Radiator blended and Degas open;

f. Radiator blended from 10% open to 100% open with Degas open; and

g. Radiator open, Heater open, Degas open and Bypass closed.

A controller can be configured to select various rotational orientationspursuant to various scenarios and conditions. Examples of such scenariosand conditions and the corresponding orientational selections includethe following (wherein the index numbers correspond to the boxed numbersshown in FIG. 12):

Potential Cold Day Scenario

Index Mode Radiator Heater Bypass Degas 1 Warm up < 95 C. OFF OFF 100%OFF 2 Warm up = 95 C. OFF 100% OFF OFF before OEM Degas shutoff time onCold Day 3 Warm up > 95 C., OFF 100% 100% 100% after OEM Degas shutofftime on Cold Day 5 Transition on Cold 1% to 25% 100% OFF 100% Day 7Economy on Cold Day 35% to 80% 100% OFF 100% 9 Power on Cold Day 50% to100% OFF 100% 100% 11 Engine Off/Overheat 100% 100% OFF 100%Potential Warm Day Scenario

Index Mode Radiator Heater Bypass Degas 1 Warm up < 95 C. OFF OFF 100%OFF 6 Transition on Warm 1% to 25% OFF 100% 100% Day 8 Economy on HotDay 35% to 80% OFF OFF 100% 10 Power on Hot Day 50% to OFF OFF 100% 100%11 Engine Off/Overheat 100% 100% OFF 100%

The valve of the present invention may be formed from any of a varietyof different materials. For example, the valve rotor may preferably beformed of an acetal copolymer known as celcon while the valve housingmay be formed of a nylon thermoplastic. Other plastics may alternativelybe used. As a further alternative, a metal may be used in thefabrication of one or both of the major components.

While a particular form of the invention has been illustrated anddescribed, it will also be apparent to those skilled in the art thatvarious modifications can be made without departing from the spirit andscope of the invention. The valve may be adapted for use in any of avariety of water-cooled engines, may be mounted in any of a variety ofspatial orientations, including but not limited to an invertedorientation, may used with any of a variety of devices for selectingrotational orientations based on a multitude of inputs while the valverotor may be rotated into position with any of a variety of drivemechanisms. Accordingly, it is not intended that the invention belimited except by the appended claims.

1. A valve for controlling fluid flow, the valve comprising: a valvehousing comprising at least one inlet port and a plurality of outletports, including a first outlet port and a second outlet port; and avalve rotor rotatably disposed within the valve housing; wherein thevalve rotor comprises a first valve portion comprising a first internalfluid passage arrangement and a second valve portion comprising a secondinternal fluid passage arrangement, the first internal fluid passagearrangement and the second internal fluid passage arrangement being influid communication with each other through a first internal fluidpassage, the first internal fluid passage arrangement providing fluidcommunication between at least one inlet port and the first outlet portand between at least one inlet port and the second internal fluidpassage arrangement, the second internal fluid passage arrangement atleast partially providing fluid communication between at least one inletport and the second outlet port, the first internal fluid passagearrangement comprising at least one conduit extending transverselyacross at least a substantial portion of the rotor and operable todirect flow of coolant across the rotor from an inlet port to an outletport and from the inlet port to the first internal fluid passage whichopens into the first internal fluid passage arrangement at a positionflowwise between an inlet port and the first outlet port; wherein thefirst internal fluid passage extends down along a rotational axis of thevalve rotor; and wherein the second internal fluid passage arrangementcomprises a pie-shaped fluid passage that extends from the firstinternal fluid passage to an opening in an outer surface of the valverotor.
 2. The valve for controlling fluid flow according to claim 1wherein at least one inlet port and the plurality of outlet ports of thevalve housing are aligned along two axially spaced planes that aresubstantially perpendicular to the rotational axis of the valve rotor.3. The valve for controlling fluid flow according to claim 1 wherein theplurality of outlet ports comprises an outlet port formed in the valvehousing that is aligned so as to be parallel with the rotational axis ofthe valve rotor.
 4. The valve for controlling fluid flow according toclaim 1 further comprising: a biasing mechanism to position the valverotor in a preselected rotational orientation relative to the valvehousing.
 5. The valve for controlling fluid flow according to claim 4wherein the biasing mechanism comprises a spring.
 6. The valve forcontrolling fluid flow according to claim 1 further comprising: a drivemechanism that is operatively connected to the valve rotor for movingthe valve rotor to selected rotational orientations within the valvehousing.
 7. The valve for controlling fluid flow according to claim 6wherein the drive mechanism comprises a motor.
 8. The valve forcontrolling fluid flow according to claim 7 wherein the motor comprisesa stepper motor.
 9. The valve for controlling fluid flow according toclaim 7 wherein the drive mechanism comprises a motor operativelyconnected to a reduction gear combination.
 10. The valve for controllingfluid flow according to claim 1 wherein the plurality of internal fluidpassages comprises a second fluid passage that extends from the firstfluid passage to at least one opening in an outer surface of the valverotor.
 11. The valve for controlling fluid flow according to claim 1wherein the plurality of internal fluid passages comprises a pluralityof axially extending internal fluid passages located within the valverotor.
 12. The valve for controlling fluid flow according to claim 1wherein the valve rotor and the valve housing are spaced apart to form agap between the valve rotor and the valve housing to permit fluid flow.13. The valve for controlling fluid flow according to claim 12 furthercomprising: at least one flexible seal between the valve rotor and theinlet port; and at least one flexible seal between the valve rotor andat least one outlet port to prevent fluid from flowing into the gap. 14.A valve for controlling fluid flow, the valve comprising: a valvehousing comprising a bottom portion, at least one inlet port, and aplurality of outlet ports, wherein the inlet port and at least oneoutlet port are substantially located in a first plane, wherein at leastone outlet port is substantially located in a second plane, wherein atleast one outlet port is located on the bottom portion of the valvehousing, wherein the first plane and the second plane are substantiallyperpendicular to a rotational axis of a valve rotor, and wherein thefirst plane and the second plane are axially spaced from each other; thevalve rotor rotatably disposed within the valve housing, wherein thevalve rotor comprises a plurality of internal fluid passages within thevalve rotor to selectively connect, in fluid relationship, the inletport with at least one outlet port; and a biasing mechanism disposedabout a shaft of the valve rotor to position the valve rotor in apreselected rotational orientation relative to the valve housing;wherein the plurality of internal fluid passages comprises a first fluidpassage that extends down along the rotational axis of the valve rotor;wherein the plurality of internal fluid passages comprises a secondfluid passage from the first fluid passage to a first surface opening inthe valve rotor in the first plane; wherein the plurality of internalfluid passages comprises a third fluid passage from the first fluidpassage to a second surface opening in the valve rotor in the firstplane; wherein the plurality of internal fluid passages comprises afourth fluid passage from the first fluid passage to a third surfaceopening in the valve rotor in the first plane; wherein the plurality ofinternal fluid passages comprises a fifth fluid passage from the firstfluid passage to a fourth surface opening in the valve rotor in thesecond plane; wherein the plurality of internal fluid passages comprisesa sixth fluid passage from the fifth fluid passage to a fifth surfaceopening in the bottom portion of the valve rotor; and wherein the sixthfluid passage comprises dual fluid passages that extend from the fifthfluid passage to dual grooved openings in the bottom portion of thevalve rotor.
 15. The valve for controlling fluid flow according to claim14 wherein the valve rotor and the valve housing are spaced apart toform a gap; wherein the valve further comprises a first flexible sealbetween the valve rotor and the inlet port; and wherein the valvefurther comprises a second flexible seal between the valve rotor and atleast one outlet port to prevent fluid from flowing into the gap.